FreeBSD/Linux Kernel Cross Reference
sys/security/mac/mac_label.c

     /*-
      * Copyright (c) 2003-2004 Networks Associates Technology, Inc.
      * Copyright (c) 2007 Robert N. M. Watson
      * All rights reserved.
      *
      * This software was developed for the FreeBSD Project in part by Network
      * Associates Laboratories, the Security Research Division of Network
      * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
      * as part of the DARPA CHATS research program.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_mac.h"
    
    #include <sys/param.h>
    #include <sys/module.h>
    #include <sys/sysctl.h>
    #include <sys/systm.h>
    
    #include <vm/uma.h>
    
    #include <security/mac/mac_framework.h>
    #include <security/mac/mac_internal.h>
    #include <security/mac/mac_policy.h>
    
    /*
     * zone_label is the UMA zone from which most labels are allocated.  Label
     * structures are initialized to zero bytes so that policies see a NULL/0
     * slot on first use, even if the policy is loaded after the label is
     * allocated for an object.
     */
    static uma_zone_t       zone_label;
    
    static int      mac_labelzone_ctor(void *mem, int size, void *arg, int flags);
    static void     mac_labelzone_dtor(void *mem, int size, void *arg);
    
    void
    mac_labelzone_init(void)
    {
    
            zone_label = uma_zcreate("MAC labels", sizeof(struct label),
                mac_labelzone_ctor, mac_labelzone_dtor, NULL, NULL,
                UMA_ALIGN_PTR, 0);
    }
    
    /*
     * mac_init_label() and mac_destroy_label() are exported so that they can be
     * used in mbuf tag initialization, where labels are not slab allocated from
     * the zone_label zone.
     */
    void
    mac_init_label(struct label *label)
    {
    
            bzero(label, sizeof(*label));
            label->l_flags = MAC_FLAG_INITIALIZED;
    }
    
    void
    mac_destroy_label(struct label *label)
    {
    
            KASSERT(label->l_flags & MAC_FLAG_INITIALIZED,
                ("destroying uninitialized label"));
    
    #ifdef DIAGNOSTIC
            bzero(label, sizeof(*label));
    #else
            label->l_flags &= ~MAC_FLAG_INITIALIZED;
    #endif
    }
    
    static int
    mac_labelzone_ctor(void *mem, int size, void *arg, int flags)
    {
            struct label *label;
   
           KASSERT(size == sizeof(*label), ("mac_labelzone_ctor: wrong size\n"));
           label = mem;
           mac_init_label(label);
           return (0);
   }
   
   static void
   mac_labelzone_dtor(void *mem, int size, void *arg)
   {
           struct label *label;
   
           KASSERT(size == sizeof(*label), ("mac_labelzone_dtor: wrong size\n"));
           label = mem;
           mac_destroy_label(label);
   }
   
   struct label *
   mac_labelzone_alloc(int flags)
   {
   
           return (uma_zalloc(zone_label, flags));
   }
   
   void
   mac_labelzone_free(struct label *label)
   {
   
           uma_zfree(zone_label, label);
   }
   
   /*
    * Functions used by policy modules to get and set label values.
    */
   intptr_t
   mac_label_get(struct label *l, int slot)
   {
   
           KASSERT(l != NULL, ("mac_label_get: NULL label"));
   
           return (l->l_perpolicy[slot]);
   }
   
   void
   mac_label_set(struct label *l, int slot, intptr_t v)
   {
   
           KASSERT(l != NULL, ("mac_label_set: NULL label"));
   
           l->l_perpolicy[slot] = v;
   }

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